Final answer:
Reflexes occur over pathways in the nervous system, involving the spinal cord and sensory and motor neurons. Reflex arcs enable quick and automatic responses to stimuli. Some reflex arcs involve only the peripheral nervous system, while others also involve the central nervous system.
Step-by-step explanation:
Reflexes occur over pathways in the nervous system. The components of these pathways include the spinal cord, which is part of the central nervous system (CNS), and the sensory and motor neurons that relay information between the periphery and the brain. Reflex arcs involve both sensory and motor components, allowing for the quick and automatic response to a stimulus without conscious thought. Some reflex arcs involve only the peripheral nervous system, while others also involve the CNS.